Multiplayer Optimization Patch

Description

Removes most instances of the MP issue where regular frame drops / lag spikes will occur, improves fps, and improves desync issues considerably. 

Does this by replacing KrokMP's sync system with my own lighter weight one, along with many other fixes.

Highly recommend pairing with my CPU Optimization Mod.

If both host and player have this mod, enables 'high performance' elder thornback sync - no more getting amputated cause of lag!

(If not, falls back to vanilla sync for that player)

Technical explanation below.

This mod took about a month of pain and suffering. Enjoy.

Installation Instructions

Simply drop into your plugins folder like any other mod.

Requires: KrokMP (Casualties Together)

PATCHNOTES (V3 / LATEST)

As it turns out, instead of trying to work with Krok's spatial fastsync.. Removing it completely fixed almost all of the lag and memory related issues. I added a lightweight sync in the background for nearby / important events, and otherwise, it just relies on the background sync loop. May introduce sync issues, but we encountered none in my testing.

The "fix" described below for the issue described is now outdated. Instead, this mod replaces the laggy half of krokMP's spatial sync with a lightweight custom one.

THIS MOD NOW OPTIMIZES BOTH THE CLIENT AND HOST EXPERIENCE

It is best combined with mods such as Jimmy's Performant Rendering and Performance Unknown, if you have a weak computer!

Client (joining a lobby)

Recommended for weak PCs / laptops; optional for everyone.

• []Steam server throughput budget; caps how many network packets are processed per frame so one backlogged frame doesn't cause your network to choke (default 256/frame)[/]

  []Reused receive buffer; stops allocating a giant buffer every frame (stock behavior is very allocation-heavy)[/]

  []Lazy Steam ID maps; skips rebuilding player ID dictionaries when the roster hasn’t changed[/]

  []Local FPS sync scale; sync timers respect your FPS, not just the host’s (thereby fixing an issue where a weak gpu chokes your network out with more work per frame when your FPS is already low)[/]

  []Registry throttle when struggling; staggers heavy client object-registry polls when FPS is low, allowing your frames to recover from heavy scenes[/]

  []Same DLL as host - one install, optimizes both host and clients gameplay[/]

  Host (lobby owner)

  • []Replaces stock FastSync with an event-driven SyncProducer - syncs what matters (nearby, dirty, opened containers) instead of brute-force scanning the whole world every tick.[/]

    []Hot / Near / Dormant sync lanes; closer & active stuff updates faster; far-away stuff updates less often.[/]

    []Uses same CoolSync packets; clients don’t need the mod to join your lobby. [/]

    []Join burst; player's queue is fed information quickly to help alleviate some of the hosts fps drops caused by a new player joining.[/]

    []Small spatial sync; low-frequency pass near each player so nothing important gets missed, replaces FastSync described below.[/]

    []Queue caps join period; allows for 30s to catch up to host before throttled, stopping desync issues for new joiners.[/]

    []Pin timeout / force-dequeue; fixes UDP issue where clients will get stuck when a packet is not ACK'd.[/]

    []Registry cull; drops far-off synced objects from the host registry so production doesn’t waste work on nobody-nearby entities.[/]

    []Skip unchanged snapshots; don’t re-pack objects that haven’t changed on regular sends.[/]

    []Container priority sync; opening a container pushes its contents immediately instead of syncing faraway containers infinitely.[/]

    []Incremental GC tuning; smaller GC slices to reduce frame spikes on long sessions.

    Both

    [*]Optimizes UI of both KrokMP and (optionally) Catpatch to not thrash memory, causing un-necessarily fast GC Heap climb.

    This extends the lifetime of the game before memory related lag eventually does set in.

    IMPLEMENTATION BELOW MAY BE OUTDATED AS THIS MOD IS UPDATED

    However, the overview of the design flaw remains accurate, so feel free to read.

    KrokMP's Design Flaw

    (Tldr at bottom)

    KrokMP causes frame drops after a certain amount of time, for one primary reason.

    The UDP structure, and it's not UDP friendly queue system.

    In the simplest terms, KrokMP uses a method in which it shotgun blasts "sync packets" across the internet. (UDP)

    Not all of them are guaranteed to come back.